Improvement in automatic relief-valves for steam fire-engines



A. MAYER.

'f-Valves for Steam Fire-Engines.

I Patented Feb. 4,1873.

Automatic R N0.135,437.

UNITED STATES PATENT QFEIoE ALVARADO MAYER, OF DETROIT, MICHIGAN.

IMPROVEMENT IN AUTOMATIC RELIEF-VALVES FOR STAM FIRE-ENGINES.

Specification forming part of Letters Patent No. 135,437, dated February4, 1S3,

To aZ-L whom 'it may concern:

Beit known that I, ALVARADO MATER, of Detroit, in the county of Wayneand State of Michigan, have invented a new and useful Improvement in anAutomatic Relief-Valve for Fire-Engines; and I do declare that thefollowing is a true and accurate description thereof, reference beinghadto the accompanyin gdrawing and to the letters of reference markedthereon and being a part of this specification, in which- Figure l is aperspective view of my device as applied to thedouble-acting pump ofasteam tire-engine. Fig. 2 is an enlarged vertical section ofthe device.

This invention has for its object to furnish one ot the hose-gates of atire-engine with reliefvalve, which will automatically open when thepressure of the Water in the hose eX- ceeds a given limit, and thusallow a part or all of' the water forced from the pump to return intothe suction-pipe, and circulate in that way as long as the pump is atwork, for the purpose of allowing the iiremen to use a pipe fitted witha stop-cock, which they may close when to throw water would causeunnecessary damage. valve the water can be shut down at the pipe at anymoment, while the engine is at work, Without danger of bursting thehose. The invention consists in a peculiarly constructed and arrangedrelief-valve, having a balanced piston playing` in acylinder above thereliefvalve, which is placed at the end of a hosegate, and, inconnection therewith, an adjustable pressure-gage actuating anequilibriumvalve through an intermediate lever and certainconnecting-pipes, all arranged and operating as more fully hereinafterset forth.

In the drawing, A represents the cylinder of a double-acting pump 5 B,its suction-pipe 5 and C, the vacuum-chamber, as commonly constructed inreciprocating steam fire-engines; D is one ofthe discharge-gates, havingthe usual stop-cock E. Where a hose-butt would be By means of thisrelief inder, F', the two being separated by a diaphragm, a, the uppercylinder being closed at the top by a head, b, Fig. 2. In the upper partof the water-way D there is a circular opening, in which is seated awing-valveJmH, from which rises a. stem, H', pa's'sigfthroughstufiing-boxes c c in the diaphragm a and head b, respectively. In thecylinder F' apistoln, I, is secured to the stem H'. d is an opening inthe side ot' the cylinder F, above the relief-valve H, which isconnected, by a pipe, J, to the suction B of the pump. K is a pipeconnecting the water-way D' with the upper part of the cylinder F' abovethe piston I, but tirst passing through the chamber L, in which is aconica-l plu g-val ve M, Whose stem M plays through stuiiing-boxes atthe top and bottom of the chamber. 'Ihis valve I term theequilibriumvalve. N is another pipe connected at one end to thewater-way D', its other end carrying a small vertical chamber, O', inthe lower part of which is seated a valve, l?, whose stem l" playsthrough a screw-threaded gland, f, tapped through the top ot' thechamber O. Between the gland and valve a spring, e, is spirally coiledabout the stem. By screwing the gland down, and thus compressing thespring, the pressure at which the valve P will open or rise isdetermined. Q is a waste-pipe leading out ofthe top ofthe cylinder F',but passing through a chamber, R, in which is a. plugvalve, S, whosestem S' plays through stuffingboxes at top and bottom of said chamber.The lower end of the stem S' rests upon the head of the stem P'. Aspring, e', may be coiled about the stem S' to insure a quick closure ofthe valve S. T is an equalizing-lever, pivoted at its middle to theouter wall of the cylinder F, one end being pivoted in a slot in thelower end ol' the stem P', and the other end pivoted in like manner tothe lower end of the stem S'. The piston I may be packed with hemp orother material, so that it will move freely in its cylinder,`but yet bewater-tight.

rlhe operation of the device is as follows: We will suppose that thespring e is adjusted to keep the valve I? seated at any pressure lessthan one hundred pounds to the square inch ou its under surface. Thevalves H, P, and S will-be closed andthe valve M open. The

engine being at work, the water passes through the way D' into the hose,exerting an upward pressure under the relief-valve H and testvalve I),and a downward pressure on the piston I. Inasmuch as the piston has agreater area than the relief-valve, it is evident that the latter willbe kept closed. Now, by turn ing the cock in the hose-pipe to shut offthe exit of the water from the hose, the pressure in the hose' andelsewhere will be suddenly increased, causing the valve P' to lift,opening the valve S, which allows the water above the piston I to iiowaway, and at the same time the lever 'I closes the valve M, to preventthe ingress of more water to the piston, which is then free to rise fromthe lpressure under the valve H, which rises and allows the water tofiow through the pipe J back into the suction, and, as long as the pumpis at work, will circulate in .this way.

Steam fire-engines are usually fitted with several gates opening from acommon forcingchannel, and but one relief-valve is necessary for theseveral gates, which will return any excess of water above the pressuredetermined by the spring to the suction, so that when playing one ormore streams, one or all of them may be backed down or shut off withoutdanger of bursting the hose, the engine continuing to work.

The working-pressure may be changed in ay moment by adjusting thescrew-glandf, and, once set, thepressure cannot be exceeded by accidentor design, thereby preventing the too frequent bursting of the hose whenat work.

What I claim as my invention, and desire to secure by Letters Patent,isg l. In pumping-engines, the combination of a relief-Valve with anadjustable pressure-gage and valve, substantially in the manner shownand described.

2. In pumpin g-en gin es, a relief-valve, H, having a piston, I, ofgreater area secured to its stem, but working in a separate cylinder,and so arranged as to keep the relief-valve closed by the pressure ofthe fluid upon both, in conneotion withindependent valves m S pforrelieving the piston from pressure, when the pressure under therelief-valve exceeds a given limit, substantially as shown and setforth.

3. The device described, consisting of water-way'D, cylinders F F',separated by the diaphragm c, relief-valve H, stem H piston I,return-pipe J, equilibrium-pipe K, chamber L, equilibrium-valve M, pipeN, chamber U, pressure-valve P, spring e, adjustable `pressuregland f,waste-pipe Q, chamber R, waste-valve S, stem Sf, and equaliZing-lever T,arranged as shown and deseribed, and for the purposes set forth.

ALVARADO MAYER.

Wit nesses H. F. EBERTS, CHARLES J. HUNT.

